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UTC+04:00
UTC+04:00
UTC+04:00
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UTC+04:00 – 2010: yellow (year-round), blue (DST Northern Hemisphere), light blue (sea areas)

Key Information

Time in Europe:
Light Blue Western European Time / Greenwich Mean Time (UTC)
Blue Western European Time / Greenwich Mean Time (UTC)
Western European Summer Time / British Summer Time / Irish Standard Time (UTC+1)
Red Central European Time (UTC+1)
Central European Summer Time (UTC+2)
Yellow Eastern European Time / Kaliningrad Time (UTC+2)
Ochre Eastern European Time (UTC+2)
Eastern European Summer Time (UTC+3)
Green Moscow Time / Turkey Time (UTC+3)
Turquoise Armenia Time / Azerbaijan Time / Georgia Time / Samara Time (UTC+4)
▉▉▉▉ Pale hues: Standard time observed all year
  ▉▉▉   Dark hues: Daylight saving time
Time in Russia
  KALT Kaliningrad Time UTC+2 (MSK−1)
  MSK Moscow Time UTC+3 (MSK±0)
  SAMT Samara Time UTC+4 (MSK+1)
  YEKT Yekaterinburg Time UTC+5 (MSK+2)
  OMST Omsk Time UTC+6 (MSK+3)
  KRAT Krasnoyarsk Time UTC+7 (MSK+4)
  IRKT Irkutsk Time UTC+8 (MSK+5)
  YAKT Yakutsk Time UTC+9 (MSK+6)
  VLAT Vladivostok Time UTC+10 (MSK+7)
  MAGT Magadan Time UTC+11 (MSK+8)
  PETT Kamchatka Time UTC+12 (MSK+9)
Time in Africa:
Light Blue Cape Verde Time[a] (UTC−1)
Blue Greenwich Mean Time (UTC)
Red
(UTC+1)[b]
Yellow
(UTC+2)
Ochre
(UTC+3)
Green East Africa Time (UTC+3)
Turquoise
(UTC+4)
a The islands of Cape Verde and the Canary Islands lie west of the African mainland.
b During Ramadan, Morocco switches to Greenwich Mean Time (UTC) and returns to UTC+1 after it ends.
d Mauritius and the Seychelles lie to the east and northeast of Madagascar, respectively.
Time in the Middle East
    UTC+02:00

UTC+03:00 		Eastern European Time /
Eastern European Summer Time
    UTC+03:00 Arabia Standard Time /
Turkey Time
    UTC+03:30 Iran Standard Time
    UTC+04:00 Gulf Standard Time
▉▉▉ Standard time observed all year
▉ Daylight saving time observed

UTC+04:00 is an identifier for a time offset from UTC of +04:00. In ISO 8601, the associated time would be written as 2019-02-07T23:28:34+04:00. This time is used in:

As standard time (year-round)

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Principal cities: Abu Dhabi, Dubai, Baku, Tbilisi, Yerevan, Samara, Muscat, Port Louis, Victoria, Saint-Denis, Stepanakert

Europe

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Eastern Europe

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South Caucasus
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Asia

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Middle East

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Africa

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Discrepancies between official UTC+04:00 and geographical UTC+04:00

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Areas in UTC+04:00 longitudes using other time zones

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Using UTC+03:00:

Using UTC+03:30:

  • Most parts of Iran

Using UTC+04:30:

  • Western parts of Afghanistan

Using UTC+05:00:

Using UTC+06:00:

Areas outside UTC+04:00 longitudes using UTC+04:00 time

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Areas between 37°30' E and 52°30' E ("physical" UTC+03:00)

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  • Caucasus region:
    • Georgia, excluding Abkhazia and South Ossetia
    • Armenia
    • Azerbaijan
  • Russia, with parts of its territories:
    • Astrakhan, Samara, Saratov and Ulyanovsk (with an exception of the very east)
    • Western half of Udmurtia
  • United Arab Emirates
  • Seychelles
  • French Southern and Antarctic Lands
    • Crozet Islands

References

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

UTC+04:00

View on Grokipedia
from Grokipedia
UTC+04:00 is a time offset from (UTC), representing four hours ahead of the reference time scale maintained by the International Bureau of Weights and Measures. This corresponds to longitudes approximately between 52.5° and 67.5° east of the and is designated as "D" in the for military timekeeping. Regions observing UTC+04:00 span parts of the , the , and the , including (Asia/Yerevan), (Asia/Baku), Georgia (Asia/Tbilisi, excluding ), (Asia/Muscat), and the (Asia/Dubai). It also covers specific oblasts in , such as (Europe/Astrakhan), Samara (Europe/Samara), (Europe/Saratov), and (Europe/Ulyanovsk), as well as island territories like (Indian/Mauritius), Réunion (Indian/Reunion), and (Indian/Mahe). Major cities in this zone include , , , , , , and , supporting economic hubs in oil production, , and . In common usage, UTC+04:00 is often referred to as Gulf Standard Time (GST) in the Arabian Peninsula countries like the UAE and Oman, where it serves as the standard for business and aviation. Unlike some other offsets, UTC+04:00 is fixed and does not observe daylight saving time in any of its current implementations, providing year-round consistency for international coordination. Historically, this offset has been stable since the mid-20th century in most areas, though some regions like parts of Russia transitioned to it in the early 2010s as part of national time zone reforms.

Introduction

Definition and Offset

UTC+04:00 is a time zone identifier representing a fixed offset of four hours ahead of (UTC), meaning clocks in this zone are set four hours later than UTC. This offset is equivalent to plus four hours (GMT+4), as UTC serves as the modern successor to GMT for global timekeeping standards. It is commonly known by names such as Gulf Standard Time (GST) in certain regions. Geographically, UTC+04:00 aligns with mean for longitudes approximately between 52.5°E and 67.5°E, based on the Earth's division into 24 zones, each spanning 15 degrees of to approximate the planet's 24-hour cycle. This range centers around 60°E, where solar noon would theoretically occur at 12:00 , providing a natural basis for time alignment in areas within this longitudinal band, though political boundaries often adjust actual implementations. In most jurisdictions using , it functions as a year-round without observance of (DST), maintaining a consistent offset throughout the calendar. This fixed nature simplifies scheduling and coordination, particularly in equatorial and tropical regions where seasonal daylight variations are minimal. , upon which is based, has been defined by standards since its formal adoption in 1972, relying on the precise oscillations of cesium-133 atoms maintained by global laboratories. To synchronize this atomic scale with 's irregular , leap seconds are occasionally inserted into UTC by the International Earth Rotation and Reference Systems Service (IERS), ensuring the difference between UTC and solar-based (UT1) remains within 0.9 seconds.

Common Names and Abbreviations

UTC+04:00, which represents a time offset of four hours ahead of , is referred to by several common names and abbreviations across different regions and applications. These designations reflect local conventions and historical usages without implying adjustments, as most areas observing this offset do not implement DST. In the , the zone is widely known as Gulf (GST), a term adopted by countries such as the and to standardize time across the region. For the countries, specific national names prevail: (AZT) in , (AMT) in , and (GET) in Georgia, each denoting the standard time for their respective territories. In the , it is called (MUT) for and (SCT) for , aligning with their fixed UTC+04:00 observance. Within Russia, the offset is designated as Samara Time (SAMT), particularly for the Volga region including Samara Oblast, where it serves as the local standard. Historically, during the Soviet era when Moscow Time (MSK) was set to UTC+03:00, this offset was commonly abbreviated as MSK+1 to indicate the one-hour advance from the reference meridian, a nomenclature used in official Soviet timekeeping documentation. In technical and computational contexts, the Internet Assigned Numbers Authority (IANA) maintains standardized identifiers in the tz database for interoperability in software systems. These include Asia/Dubai for Gulf Standard Time areas, Asia/Baku for Azerbaijan, Asia/Tbilisi for Georgia, Asia/Yerevan for Armenia, Europe/Samara for Samara Time, Indian/Mauritius for Mauritius, Indian/Mahe for Seychelles, and Indian/Reunion for Réunion, ensuring precise handling of historical and current offsets.

Historical Development

Early Adoption in Russia

The adoption of UTC+04:00 in Russian territories began with the Soviet Union's time zone reforms in 1930. On June 21, 1930, the issued a decree advancing all clocks by one hour nationwide, establishing "Decree Time" as a permanent daylight saving adjustment to conserve energy and standardize operations across the vast union. This shift set to UTC+03:00 and introduced Kuibyshev Time—one hour ahead of Moscow, aligning it with UTC+04:00—for the region around the city of Kuibyshev (now Samara), which served as a key industrial and . Following , the Soviet time zone system underwent adjustments to incorporate annexed territories and streamline administration, but the foundational structure persisted. remained the base at year-round under Decree Time, while the Samara region (encompassing Kuibyshev Oblast) continued as a +1 offset, fixed at UTC+04:00, to better match local and economic activities in the area. These postwar alignments emphasized uniformity, with minimal disruptions to the 1930 offsets until the late . In , the Soviet government formalized its division into 11 time zones via decree, explicitly designating the Samara Time Zone—spanning several republics and oblasts—as equivalent to during . This measure, effective from April 1, also introduced seasonal across the USSR, advancing clocks by one hour from spring to autumn, which temporarily shifted the zone to and reinforced centralized control over temporal coordination. The 1981 framework solidified Kuibyshev Time's role in eastern until the city's renaming back to Samara in 1991. The 2010–2011 reforms marked a significant evolution, as abolished nationwide to address public complaints about health and productivity impacts. On March 28, 2010, the Samara region briefly shifted to alongside , but the March 28, 2011, decree advanced all Russian clocks by one hour permanently, restoring and fixing (SAMT) at UTC+04:00 without seasonal changes and reducing the overall number of zones. This also led to the adoption of UTC+04:00 in other regions like , , and Oblasts during the same reforms. This cemented UTC+04:00 as the standard for the region, a practice that has continued in select .

Adoption in Caucasus and Gulf States

Following the , the nations of , , and Georgia each adopted as their zone in the early to better align with local and foster economic ties with neighboring regions. In , this transition occurred on September 23, 1991, shortly after declaring on September 21, 1991, when clocks shifted from Armenia Summer Time to at without further offset adjustment. Azerbaijan formalized its use of (AZT) at on September 26, 1992, following on August 30, 1991, maintaining the offset as the base for any seasonal adjustments. Georgia adopted (GET) at following on April 9, 1991, reflecting lingering Russian influence in regional standardization efforts, and discontinued after October 30, 2005, establishing as permanent . In the Gulf States, the (UAE) adopted Gulf Standard Time (GST) at in 1972, one year after independence from British protection on December 2, 1971, to synchronize with and support growing regional trade networks. has used GST at since independence in 1970, aligning its timekeeping with adjacent Gulf partners while opting against . This consistency has facilitated cross-border commerce without seasonal disruptions. Under British colonial administration, introduced (MUT) at UTC+04:00 on January 1, 1907, replacing local mean time to standardize operations across the colony. adopted Seychelles Time (SCT) at UTC+04:00 during the British colonial period, retaining it post-independence in for continuity in international relations and shipping. The French territory of the , part of the , uses UTC+04:00 to support the islands' role in ongoing research stations without daylight saving adjustments.

Current Usage as Standard Time

Europe and Caucasus

In the Caucasus region, which spans the border between and , UTC+04:00 serves as the standard time zone for several independent countries, reflecting their geographical position and historical ties to Russian timekeeping systems. These nations adopted the offset to align with regional economic and transportation networks, without observing . observes (AMT), which is UTC+04:00 year-round, encompassing the entire country of approximately 3 million people. The capital, , and major cities like operate on this time, facilitating synchronization with neighboring states and international trade routes. This uniform nationwide application supports 's integration into Eurasian economic frameworks. Azerbaijan employs (AZT) at UTC+04:00 across its territory, including the capital and the region, for a exceeding 10 million. This choice accommodates Azerbaijan's role as an energy exporter, aligning operations in the basin with global markets. No daylight saving adjustments are made, ensuring consistent scheduling for oil and gas infrastructure. Georgia uses Georgia Standard Time (GET), equivalent to , throughout its internationally recognized territory, home to about 3.7 million residents, with as the capital. This applies to regions like and but excludes the disputed territories of , which follow Moscow Standard Time () due to their alignment with Russian administration. Georgia's adoption of GET promotes coordination with European partners while maintaining regional distinctions. No other sovereign European countries utilize UTC+04:00 as their primary standard time, though Russia's transcontinental expanse includes European-adjacent oblasts like Samara that share this offset, highlighting the zone's broader Eurasian footprint.

Middle East

In the , UTC+04:00 serves as the standard time zone for two (GCC) member states, facilitating regional economic coordination despite variations in time observance among GCC countries. This offset, known as Gulf Standard Time (GST), aligns these nations with and energy sectors, particularly in oil and gas, where synchronized operations across borders are essential. The (UAE) uniformly observes GST (UTC+04:00) nationwide, without (DST), encompassing all seven emirates and major urban centers such as , the capital, and , a global financial hub. This consistent supports the UAE's diverse economy, including , , and , serving a of approximately 11.4 million residents as of 2025. The absence of DST has been maintained since the country's formation in , promoting stability in business scheduling. Oman also adheres to GST (UTC+04:00) across its entire territory, with as the capital and principal port city, and has never implemented DST in its modern history. This time zone choice reflects Oman's strategic position in international shipping and energy exports, accommodating a population of about 5.5 million in 2025. The fixed offset enhances coordination with neighboring UAE for cross-border trade within the GCC framework. No other countries in the currently use UTC+04:00 as their standard time, with most regional states, including other GCC members like and , operating on to better align with in their latitudes. This divergence underscores the GCC's emphasis on economic over uniform time zones, allowing flexible bilateral alignments between UAE, , and their UTC+03 partners.

Africa and Indian Ocean Islands

UTC+04:00 is used as the standard time zone across several island nations and territories in the , reflecting a legacy of British and French colonial influences that standardized timekeeping in these regions for administrative and maritime purposes. observes (MUT), which is UTC+04:00 nationwide, including its capital, . The island nation's population is approximately 1.3 million. The , an archipelago comprising 115 islands, uses Seychelles Time (SCT) at UTC+04:00 throughout the country, with its capital in Victoria. , a French overseas department, follows Réunion Time (RET) at UTC+04:00, centered in its capital, Saint-Denis, and home to a of around 870,000. No mainland African countries use UTC+04:00 as their standard time zone.

Other Territories

The Samara Time Zone (SAMT), observing a fixed UTC+04:00 offset without daylight saving time, covers several federal subjects in the eastern European part of . These regions include , (with its capital Samara serving as the zone's namesake and primary urban center), , , and the Udmurt Republic. This zone spans the middle River basin and adjacent areas, supporting diverse economic activities such as petroleum extraction in Astrakhan, automotive manufacturing in the Udmurt Republic's capital , and agricultural production across the oblasts. The combined population of these territories is approximately 9.5 million residents, representing a significant portion of Russia's . Russia standardized the Samara Time Zone at on March 26, 2011, as part of a nationwide reform that eliminated and realigned offsets to better match geographical longitudes. Prior to this, the areas had followed () with seasonal adjustments, but the permanent +4 offset was adopted to reduce discrepancies with local noon times, which occur around 60° east longitude in this region. Samara, with over 1.1 million inhabitants, functions as the economic and transportation hub, hosting major industries like oil refining and . The zone's stability has facilitated consistent scheduling for cross-regional trade and infrastructure, such as the shipping routes. Volgograd Oblast formerly observed UTC+04:00 within this zone until a shift on December 27, 2020, when it transitioned to Moscow Standard Time (UTC+03:00) to enhance alignment with central Russian economic activities and federal administration. This change, effective at 2:00 a.m. local time, followed public consultations and aimed to simplify interactions with . As of November 2025, the Samara Time Zone remains unchanged, with no proposed adjustments reported in Russian federal legislation or timekeeping authorities.

Discrepancies with Geographical Time

Areas in Geographical UTC+04 Using Different Zones

The geographical UTC+04:00 time zone corresponds to longitudes between 52.5°E and 67.5°E, based on the standard division of the world into 15° longitude bands for mean solar time. Within this range, several regions in Central Asia observe UTC+05:00 instead, reflecting historical administrative decisions and efforts to align with neighboring areas for economic and logistical coordination. Turkmenistan, whose territory primarily falls between approximately 52°E and 66°E, observes (TMT) at UTC+05:00 year-round, including in its capital, . This offset has been in place since the post-Soviet era, continuing a legacy from the where Central Asian republics were assigned time zones offset from geographical norms to synchronize with broader union-wide operations. Uzbekistan, with much of its land area between 56°E and 67°E, uses Uzbekistan Time (UZT) at UTC+05:00 nationwide, encompassing its capital, . Like , this choice stems from Soviet-era zoning practices that prioritized political and economic unity across republics over strict longitudinal alignment, a pattern retained after independence to maintain compatibility with adjacent states. In , western regions including , , and parts of Mangystau, , and West Kazakhstan—many of which lie within the 52.5°E to 67.5°E band—observe following the nationwide unification to a single time zone effective March 1, 2024. This reform shifted eastern areas from to match the west, driven by political goals of national cohesion and alignment with neighbors like and , while inheriting Soviet legacies of non-geographical offsets for administrative efficiency. However, as of 2025, the change has sparked public discontent and concerns over disruptions to circadian rhythms due to the country's vast east-west span.

Areas Using UTC+04 Outside Geographical Range

In , the Samara Time Zone (SAMT) employs UTC+04:00 across regions such as and the , encompassing longitudes primarily between 48°E and 55°E. These territories include areas west of 52.5°E, such as central at approximately 50°E, where the geographical alignment would correspond to based on calculations. Eastern portions of , spanning roughly 53°E to 55°E, fall within the standard UTC+04:00 geographical range but are unified under this offset for administrative consistency. The adoption of UTC+04:00 in these western segments stems from economic and logistical integration with the Moscow Time Zone (MSK, ), facilitating synchronized operations in transportation, industry, and commerce across . In the Caucasus region, Georgia maintains UTC+04:00 (, GET) throughout its territory, including western areas near 40°E longitude, such as parts of the coast, despite their closer solar alignment to . This national uniformity was established in 2005 when Georgia reverted from a brief period (adopted in 2004 for better European business hours overlap) to align with neighboring states like and , promoting regional coordination in and communications. Similarly, shifted to permanent in 2012 by eliminating , citing economic benefits from standardized hours with key partners in the zone, including reduced discrepancies in international dealings. has likewise used year-round since 2016, following the abolition of DST, to support oil industry operations and synchronization with Gulf and Russian markets. The Gulf states of the (UAE) and observe as Gulf Standard Time (GST), applied uniformly despite spanning longitudes from about 51°E to 56°E in the UAE and 52°E to 60°E in . Western UAE areas near the border with , around 51°E, lie outside the 52.5°E–67.5°E geographical band for , aligning instead with solar norms, yet adopt GST for seamless integration with eastern emirates and regional commerce. , with its eastern extents approaching 60°E, fixes to bolster trade uniformity across the , avoiding fragmentation that could complicate shipping and financial transactions with neighbors like the UAE. This extension of beyond its geographical longitude range (52.5°E–67.5°E) introduces deviations of up to one hour from local mean in affected western areas, as each 15° of longitude equates to roughly of solar offset. Such discrepancies shift clock-based dawn and dusk timings— for instance, advancing sunrise by up to an hour relative to solar noon—potentially influencing agricultural schedules, energy usage patterns, and human circadian rhythms in these regions.

References

  1. https://www.timeanddate.com/worldclock/timezone/utc4
  2. https://timezonedb.com/time-zones
  3. https://www.timeanddate.com/time/zones/gst
  4. https://www.timeanddate.com/time/utc-offsets.html
  5. https://gisgeography.com/world-time-zone-map/
  6. https://www.timetemperature.com/time-zone-maps/world-time-zone-map.shtml
  7. https://www.worldtimeserver.com/learn/time-zones-with-no-daylight-saving-time/
  8. https://www.itu.int/hub/2023/07/coordinated-universal-time-an-overview/
  9. https://www.cnmoc.usff.navy.mil/Our-Commands/United-States-Naval-Observatory/Precise-Time-Department/Global-Positioning-System/USNO-GPS-Time-Transfer/Leap-Seconds/
  10. https://www.timeanddate.com/time/zones/
  11. https://www.timeanddate.com/time/zones/azt
  12. https://timeapi.io/documentation/iana-timezones
  13. https://www.timeanddate.com/time/change/russia?year=1930
  14. https://statoids.com/tru.html
  15. https://www.timeanddate.com/time/change/russia?year=1981
  16. https://www.timeanddate.com/news/time/russia-reduces-time-zones.html
  17. https://www.timeanddate.com/time/zone/armenia/yerevan?year=1991
  18. https://www.timeanddate.com/time/zone/azerbaijan/baku?year=1992
  19. https://www.timeanddate.com/time/zone/georgia/tbilisi?year=1990
  20. https://www.timeanddate.com/time/change/georgia?year=2005
  21. https://dev.housing.arizona.edu/abu-dhabi-uae-time
  22. https://www.timeanddate.com/time/change/mauritius?year=1907
  23. https://www.timeanddate.com/time/zone/seychelles
  24. https://www.timeanddate.com/time/zone/france/ile-de-la-possession-crozet-islands
  25. https://www.timeanddate.com/time/zone/armenia
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  27. https://data.worldbank.org/indicator/SP.POP.TOTL?locations=AM
  28. https://www.timeanddate.com/time/zone/azerbaijan
  29. https://www.timeanddate.com/worldclock/azerbaijan/baku
  30. https://www.timeanddate.com/time/zone/azerbaijan/nagorno-karabakh
  31. https://www.timeanddate.com/time/zone/georgia
  32. https://www.timeanddate.com/worldclock/georgia/tbilisi
  33. https://www.timeanddate.com/time/zone/georgia/abkhazia
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  40. https://www.worlddata.info/timezones/gst-gulf-time.php
  41. https://www.britannica.com/place/Seychelles/History
  42. https://www.britannica.com/place/Mauritius
  43. https://www.timeanddate.com/time/zones/mut
  44. https://24timezones.com/Port-Louis/time-zone
  45. https://www.worldometers.info/world-population/mauritius-population/
  46. https://www.timeanddate.com/time/zones/sct
  47. https://24timezones.com/Victoria/time-zone
  48. https://www.seychelles.com/aboutus/aboutseychelles
  49. https://24timezones.com/Saint-Denis/time-zone
  50. https://www.worldometers.info/world-population/reunion-population/
  51. https://www.countries-ofthe-world.com/time-zones-russia.html
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  53. https://www.citypopulation.de/en/russia/admin/
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  57. https://www.timeanddate.com/time/zones/tmt
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  61. https://www.timeanddate.com/news/time/kazakhstan-single-time-zone.html
  62. https://eurasianet.org/single-time-zone-in-kazakhstan-messing-with-citizens-circadian-rhythms
  63. https://www.rferl.org/a/33249639.html
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  65. https://lidenz.com/what-is-the-time-in-russia-the-country-with-11-time-zones/
  66. https://www.rferl.org/a/armenia_to_end_seasonal_clock_changes/24464145.html
  67. https://royalstaruae.com/uae-time-difference-with-countries/
  68. https://www.timeanddate.com/worldclock/oman/muscat
  69. https://www.calculator.net/time-zone-calculator.html
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